diff --git a/lib/bcoin/http/rpc.js b/lib/bcoin/http/rpc.js
index 9447d13c..347c5b76 100644
--- a/lib/bcoin/http/rpc.js
+++ b/lib/bcoin/http/rpc.js
@@ -11,6 +11,13 @@ var utils = require('../utils');
 var IP = require('../ip');
 var assert = utils.assert;
 var constants = bcoin.protocol.constants;
+var fs;
+
+try {
+  fs = require('f' + 's');
+} catch (e) {
+  ;
+}
 
 function RPC(node) {
   if (!(this instanceof RPC))
@@ -2509,7 +2516,6 @@ RPC.prototype.setmocktime = function setmocktime(args, callback) {
  */
 
 RPC.prototype.resendwallettransactions = function resendwallettransactions(args, callback) {
-  var self = this;
   var hashes = [];
   var i, tx;
 
@@ -2588,7 +2594,7 @@ RPC.prototype.dumpwallet = function dumpwallet(args, callback) {
   if (!args[0] || typeof args[0] !== 'string')
     return callback(new RPCError('Invalid parameter.'));
 
-  file = utils.normalize(args[0]);
+  file = toString(args[0]);
   time = utils.date();
   out = [
     utils.fmt('# Wallet Dump created by BCoin %s', constants.USER_VERSION),
@@ -2637,7 +2643,14 @@ RPC.prototype.dumpwallet = function dumpwallet(args, callback) {
 
       out = out.join('\n');
 
-      callback(null, out);
+      if (!fs)
+        return callback(null, out);
+
+      fs.writeFile(file, out, function(err) {
+        if (err)
+          return callback(err);
+        callback(null, out);
+      });
     });
   });
 };
@@ -3112,7 +3125,10 @@ RPC.prototype.importwallet = function importwallet(args, callback) {
   if (args.help || args.length !== 1)
     return callback(new RPCError('importwallet "filename"'));
 
-  file = toString(args[0]),
+  file = toString(args[0]);
+
+  if (!fs)
+    return callback(new RPCError('FS not available.'));
 
   fs.readFile(file, 'utf8', function(err, data) {
     if (err)
@@ -3152,7 +3168,7 @@ RPC.prototype.importwallet = function importwallet(args, callback) {
       self.wallet.importKey(0, key, null, next);
     }, function(err) {
       if (err)
-        return callback(err)
+        return callback(err);
 
       self.walletdb.rescan(self.chain.db, 0, function(err) {
         if (err)
diff --git a/lib/bcoin/keyring.js b/lib/bcoin/keyring.js
index d6378769..521754ae 100644
--- a/lib/bcoin/keyring.js
+++ b/lib/bcoin/keyring.js
@@ -784,7 +784,6 @@ KeyRing.fromJSON = function fromJSON(json) {
 
 KeyRing.prototype.toRaw = function toRaw(writer) {
   var p = new BufferWriter(writer);
-  var i;
 
   p.writeU8(this.witness ? 1 : 0);
 
@@ -812,7 +811,7 @@ KeyRing.prototype.toRaw = function toRaw(writer) {
 
 KeyRing.prototype.fromRaw = function fromRaw(data, network) {
   var p = new BufferReader(data);
-  var i, count, key;
+  var key;
 
   this.network = bcoin.network.get(network);
   this.witness = p.readU8() === 1;
diff --git a/lib/bcoin/mtx.js b/lib/bcoin/mtx.js
index 6f464659..73113b2e 100644
--- a/lib/bcoin/mtx.js
+++ b/lib/bcoin/mtx.js
@@ -704,6 +704,7 @@ MTX.prototype.isSigned = function isSigned() {
     if (!this.isInputSigned(i))
       return false;
   }
+  return true;
 };
 
 /**
@@ -714,7 +715,7 @@ MTX.prototype.isSigned = function isSigned() {
 
 MTX.prototype.isInputSigned = function isInputSigned(index) {
   var input = this.inputs[index];
-  var prev, vector, m, redeem, j, result;
+  var prev, vector, redeem, result;
 
   assert(input, 'Input does not exist.');
 
@@ -756,7 +757,7 @@ MTX.prototype.isInputSigned = function isInputSigned(index) {
 
   if (redeem) {
     redeem = vector.pop();
-    result = this.isVectorSigned(prev);
+    result = this.isVectorSigned(prev, vector);
     vector.push(redeem);
     return result;
   }
@@ -772,7 +773,7 @@ MTX.prototype.isInputSigned = function isInputSigned(index) {
  */
 
 MTX.prototype.isVectorSigned = function isVectorSigned(prev, vector) {
-  var m;
+  var i, m;
 
   if (prev.isPubkey()) {
     if (!Script.isSignature(vector.get(0)))
@@ -791,8 +792,8 @@ MTX.prototype.isVectorSigned = function isVectorSigned(prev, vector) {
     m = prev.getSmall(0);
 
     // Ensure all members are signatures.
-    for (j = 1; j < vector.length; j++) {
-      if (!Script.isSignature(vector.get(j)))
+    for (i = 1; i < vector.length; i++) {
+      if (!Script.isSignature(vector.get(i)))
         return false;
     }
 
@@ -955,7 +956,7 @@ MTX.prototype.isInputScripted = function isInputScripted(index) {
 MTX.prototype.maxSize = function maxSize(options) {
   var scale = constants.WITNESS_SCALE_FACTOR;
   var i, j, input, total, size, prev, m, n, sz;
-  var witness, hadWitness, redeem, wallet;
+  var witness, hadWitness, redeem;
 
   if (!options && this.isScripted())
     return this.getVirtualSize();
diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index f27d4db3..0d6527be 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -403,8 +403,10 @@ utils.hrtime = function hrtime(time) {
     return [sec, ms * 1e6];
   }
 
-  return Array.isArray(time) && time.length == 2 ?
-    process.hrtime(time) : process.hrtime();
+  if (time)
+    return process.hrtime(time);
+
+  return process.hrtime();
 };
 
 /**